1. Field of the Invention
The invention is related to the field of communication networks, and in particular, to implementing the feature of anonymous call blocking in wireless networks.
2. Statement of the Problem
Telephone service providers offer many features to service subscribers. One feature offered to traditional wire line subscribers is anonymous call blocking. Anonymous call blocking allows a called party to block calls that do not provide caller ID information.
Assume that a calling party places a call to telephone number. An originating switch receives the call and generates call signaling to set up the call. The call signaling typically includes caller ID information, such as the name and number of the calling party. The originating switch then transmits the call signaling to a terminating switch. Responsive to receiving the call signaling, the terminating switch transmits ring tones and the caller ID information to the called party. If the called party has caller ID equipment, then the caller ID equipment displays the caller ID information and the called party can see who is calling before picking up the phone.
The calling party may prevent the caller ID information from getting transmitted to the called party. A call with no caller ID information is termed an “anonymous” call. This is often the case for telemarketing calls and other courtesy calls. For anonymous calls, the originating switch does not transmit caller ID information in the call signaling.
A called party may prevent anonymous calls from being routed to their telephone by subscribing to the anonymous call blocking feature. When the terminating switch receives call signaling for a call and identifies that the call signaling does not include caller ID information, the terminating switch blocks the call and the originating switch plays an announcement to the calling party that the called party does not accept anonymous calls.
One problem with the current anonymous call blocking feature is that the feature is only effectively implemented and offered for wire line telephone networks. Unfortunately, the anonymous call blocking feature is not currently offered for cellular networks or other wireless networks. Anonymous call blocking could be a very important feature in wireless networks. For instance, as number portability becomes popular, a wire line subscriber may port their wire line number to their wireless phone. If the wire line number is on a telemarketing list, the wireless phone may receive anonymous calls from telemarketers and other businesses. The wireless subscriber may wish not to be disturbed by telemarketers and other anonymous callers, especially if the wireless subscriber is paying for the service by the minute. Therefore, it would be advantageous to have a network-based solution for blocking anonymous calls in wireless networks.